Swab



Jan. 17, 1928.

H. J. QUINTRELL SWAB Filed March 2.3, 1927 Patented Jan. 17, 192,

YUNITED STATES Y HRRY .T. QUINTRELL, OFSOUTHGATE, CALFORNIA.

swan.

Application filed March 23 This invention relates to s vabs and more particularly to that type oi. swab -constructed to permit escape ot some of the liquid past the swab when the partial vacuum resulting -li'roln the swabbing` operation reaches a predetermined value. The advantages oit this to avoid liability oi the well casing or tubing collapsing becauseof the difference inv pressures within and without said casing or tubing. 1t follows from this that one of the principal objects ot the invention is to insure against collapsing of the casing or tubing when pulling a vacuum by operation ot the swab.

order to obtain the advantages that may be derivei'l from the use of this invention.

Still further objects are simplicity of con' struction and inexpensivenessot manul'eL 4 ture ot the swab.

The accompanying drawings illustrate thej in vention.

Figure 1 is a longitudinal viewoli a swab embodying the inventon, a 'fragment of well casing or tubing, in which the swab is positioned, being shown in section. j Y.

Figure 2 is an enlarged 'liragmental section on the line indicated by 2 2, Figure 1, the well casing or tubing being omitted.

Figures 8, 1 and 5 are transverse sections on the lines indicated by 3 3, 4 4, and 5 5 respectively, Figure 2. j

Referring to the drawings, a swab of well known construction .is Aindicated in general by the character (i and comprises a plunger 7 a rubber 8, a pipe 9, a lower flange 1() on the pipe i) and a nut 11 screw threaded on the pipe il to force the flange 10 toward the j ilunger so as to expand the rubber 8 into close Contact with the inner face ot the casingl or tubing. The swab also comprises a alve cage 12 screwed onto the lower end oi? the pipe i), which cm'lmunical'es with the interior ot said valve rage, a lock nut 13 on the pipe S) to prevent unscrewing of the cage 12,"a valve seat 14: with in the valvecage and a ball. valve 15 in the cage to close onto the seat 14. The construction and operation ot swabs of the type just described are well` known in this art and, accordingly it is unneci-ssary to describe them more in detail.

The specialv features of the invention,

which may either be constructed as a part of 1927. Serial N0. 177,564.

the swab above described or as a separate unit that maybe assembled with a swab already mamltactured, will now be described.`

In swabs oi? the type described above already manufactm-ed, the valve seat 1l is held in place by a bushing, not shown, adapted to engage the internal screw threads 16 of the lower end of the cage 12. ln lieu oi said bushing I provide a" chambereifl body 1i' to engage the screw threads 1G and the valve seat 11. The body 17 is provided with an upper chamber 18 provided with ports 19 that-open to the outer face of the body 17. The chamber 18 opens to the upper end of the body 17 and communicates with the bore oit the valve seat 1d. The body 17 is also provided with a lciver valve chamber 20 in which is positioned a'valve plug 21 that is urged bya spring 22` in the chamber y2,() into position to close a port28 that opens from the upper end of the `chamber 20. The port 23 passes around the chamber 18 and conin'lunicates at its upper end with the interior ot the cage 12. In this particular instai'ice, the port 23 has a number of branches 24 arranged at different points around the cha/nw.. ber 18. The port 23 constitutes a means Jfor by-passing liquid around the ball valve 15 so that pressure ot the liquid column beingl raised willbe imposed upon the valve 21 and the spring 22. The spring 22 will be made ot' a predetermined strength so that the valve 21 will open only when there is a predetermined ditference between the pressures above and below the valve 2l. The upper end of the spring 22 engages thevalve 21 and the lower end ol said spring seats against the inner tace ot' a hollow spring seat 25, the bore ol said spring seat being indicated at 2G and ai?- iording passage for liquid to and troni the chamber' 20L The spring` seat 25 adjustable, being screwed into the lower end of Jdie chamber 20, thus affording a means to adjust the pressure ot the spring 22 on the valve 21. The spring 22 will be adjusted to pin-mit the valve 21 to open betere the partial vacuum created. below the rubber 8, during elevation ot the swab, reaches a suflicient value to `cause collapsing of the walls o1 the well casing or tubing by a great difference in pressures within and Without said easing or tubing consequent upon raising of the swab.

The invention described above operates as follows: The body 17, and the parts supported thereby, having been attached to the valve cage 12, and the plunger 7 having lli been connected, in a manner well understood in this art, to the rods by which it is operated, the swab will be lowered through the well casing or tubing to the lower end thereof and the fluid beneath the swab will pass through the swab by entering the ports 19 to the chamber 18 and raising the ball valve off of its seat,

After the swab has been lowered to the desired level, it will be elevated, thus carrying with it the column of liquid and other materials that may be in the liquid, and, since the rubber 8 closely lits the well casing or tubing,4 a partial vacuum will be created in the inside of the well casing or tubing below said rubber. The well casing or tubing will, of course, withstand a considerable difference in external and internal pressures, but there is a dillerence in pressure beyond which it is unsafe to` go, t'or,'if the partial vacuum within the casing or tubing should reach a value greater than the strength of thecasing or tubing, collapsing of said casing or tubing with all its attendant evils would result. The pressure of the liquid column is imposed upon the valve 21 and, when the combined fluid pressure and spring pressure below the valve 21 becomes less than the pressure above the valve 21, said valve 21 opens and permits escape of `liquid from above the valve 21 to below said valve, thus increasing the pressurebelow the valve-21. As soon as the combined pressures of the spring and fluid below the valve 21 are greater than the liquid pressure upon the valve 21, said valve will Close. Thus as the swab travels upward in the well casing or tubing the valve 21 will open whenever the partial vacuum below the swab reaches a predetermined value, and will close when said partial vacuum has to some degree been relieved.

Though, by use of this invention, some of the liquid being raised is allowed to escape back into the well, that is preferable to collapsing the casing or tubing and, of course, the amount of liquid that thus escapes is small in comparison to the amount raised by the swab.

I claim:

1. A swab comprising a liquid-elevating means including a valve cage, a valve seat in said cage, a valve to close onto said seat, a body connected with the lower end of the cage and provided with upper and lower chambers, the upper chamber communicating with the bore of the valve seat and provided with a port opening to the outer face ot' said body, the lower chamber provided with a port opening past the valve to the interior of the valve cage, a valve in the lower chamber to close the second mentioned port, and a spring yieldingly holding the second mentioned valve closed.

2. The unit described comprising a body adapted for connecting with the lower end of an ordinary well swab, the body provided with upper and lower chambers, the upper chamber opening tothe upper end oi' the body and provided with al port opening to the outer face ot said body, the lower chamber provided with a port opening past the upper chamber to the upper end ot the body, a valve in the lower chamber to close the second mentioned port, and a spring yieldingly holding the valve closed.

3. The unit described comprising a bodyV provided with external screw threads at one ond and provided with upper and lower chambers, the upper chamber opening to the screw threaded end of the `body and provided with a port opening to the outer face of said body, the lower chamber provided with a port openin past the upper chamber to the screw threaded end of the body, a valve in the lower chamber to close the second mentioned port, and a spring yieldingly holding the valve closed.

4. The unit described comprising a body adapted for connecting with the lower end of an ordinary well swab, the body provided with a chamber opening to the upper end of the body and provided with a port opening to the outer face of said body, the body provided with a port opening past the chan1- ber to the upper end of the body and extending downwardly beneath the chamber, a valve beneath said second mentioned port, and a spring yeldingly holding the valve in position to close the second mentioned port.

Signed at Los Angeles, this 16th day of March, 1927.

HARRY J. QUTNTRELTJ. 

